A serious accident has occurred at Alton Towers, one of the UK's leading theme parks.

Two carriages on the popular Smiler roller coaster collided today at the Staffordshire attraction. The collision happened at around 2pm this afternoon, with 16 people sitting in one carriage, while the other, thankfully, was empty.

Staff are now evacuating the area, with emergency services building a platform to allow other members of the public to leave the stalled ride.

The Smiler opened back in May 2013, and is situated in the X Sector area of the park. Lasting 165 seconds, the ride accommodates 16 passengers per ride train and runs for a length of 1,170m. It reaches top speeds of 85 Km/h and features 14 loops, with its highest drop measuring 30 metres. Alton Towers attracts almost 3 million visitors a year.

Merlin Entertainment, which runs Alton Towers, has released the following statement

There has been an incident on the Smiler this afternoon involving two carriages coming together on a low section of the track. One of the carriages was empty and the other had 16 guests in.

The Resort's fully qualified First Responders were on the scene immediately to assist with the evacuation which is ongoing, and the area has been closed to allow for access to emergency services vehicles. To ensure the safe and timely evacuation of guests a platform is being constructed. This will take a few minutes but will enable us to proceed more quickly.

There will be a full investigation once we have recovered the guests who are our priority.